Hybrid Finite Volume and Discontinuous Galerkin Method with Dynamic Overset Noise Source Identification for Acoustics Prediction

摘要

A novel approach for the accurate modeling of acoustic signal propagation is presented. In this work, a well-established unstructured mesh CFD solver is utilized to efficiently model the physics associated with acoustics generation and a high-order accurate discontinuous Galerkin solver is then used to accurately propagate acoustic signals across large distances with minimal dissipation and dispersion. The two solvers operate on separate overlapping meshes and an innovative dynamic overset coupling approach is used to transmit the acoustic signals to the farfield in a one-way manner in which the acoustics prediction is unaffected by the outer acoustic propagation physics. The acoustic source region is identified on-the-fly by means of a specialized dynamic hole-cutting and overset grid assembly approach based on proximity to regions of high pressure variance or Lighthill's stress. The framework upon which the solvers are developed is described along with details outlining the dynamic overset grid assembly and interpolation methods. Detailed parametric studies are conducted to demonstrate dynamic acoustic source identification using both statistical and instantaneous flow properties, and results are presented which verify the accuracy of the capability for aeroacoustic predictions.